- BACKGROUND: The increasing population of very old intensive care patients (VIPs) is a major challenge currently faced by clinicians and policymakers. Reliable indicators of VIPs' prognosis and purposefulness of their admission to the intensive care unit (ICU) are urgently needed. METHODS: This is a report from the Polish sample of the VIP1 multicentre cohort study (NCT03134807). Patients ≥ 80 years of age admitted to the ICU were included in the study. Information on the type and reason for admission, demographics, utilisation of ICU procedures, ICU length of stay, organ dysfunction and the decision to apply end-of-life care was collected. The primary objective was to investigate the impact of frailty syndrome on ICU and 30-day survival of VIPs. Frailty was assessed with the Clinical Frailty Scale (≥ 5 points on a scale of 1-9). RESULTS: We enrolled 272 participants with a median age of 84 (81-87) years. Frailty was diagnosed in 170 (62.5%) patients. The ICU and 30-day survival rates were equal to 54.6% and 47.3% respectively. Three variables were found to significantly increase the odds of death in the ICU in a multiple logistic regression model: SOFA score (OR = 1.16; 95%CI 1.16-1.24), acute mode of admission (OR = 5.1; 95%CI 1.67-15.57) and frailty (OR = 2.25; 95%CI 1.26-4.01). CONCLUSION: Measuring frailty in critically ill older adults can facilitate making more informed clinical decisions and help avoid futile interventions.